US launches rare air strike on Syrian government-backed troops

The US military launched airstrikes on Syrian government-backed troops on Wednesday after as many as 500 attackers began what an official said appeared to be a coordinated assault on Syrian opposition forces accompanied by US advisers in Deir el-Zour Province.

The official said the strikes were in self-defence after the pro-government forces began firing artillery and tank rounds at the US-backed Syrian Democratic Forces. About 100 of the attackers were killed, the official said.